<label class="container">
  <input type="checkbox" checked="checked" />
  <div class="checkmark"></div>
</label>

<style>
/* From Uiverse.io by myshy13  - Tags: checkbox */
.container input {
  opacity: 0;
  cursor: pointer;
  display: none;
}

.container {
  display: block;
  position: relative;
  cursor: pointer;
  font-size: 20px;
  user-select: none;
}

.checkmark {
  transition: 0.5s ease;
  border-radius: 0.2em;
}

.checkmark {
  position: relative;
  top: 0;
  left: 0;
  height: 1.3em;
  width: 1.3em;
  background-color: #ccc;
}
.container input:checked ~ .checkmark {
  background-color: #b30000;
  box-shadow: #ff2929 0px 0px 1em;
  outline: rgb(139, 0, 0) 3px solid;
}

.checkmark:after {
  content: "";
  position: absolute;
  display: none;
}

.container input:checked ~ .checkmark::after {
  display: block;
}

.container .checkmark::after {
  left: 0.45em;
  top: 0.25em;
  width: 0.25em;
  height: 0.5em;
  border: solid white;
  border-width: 0 0.15em 0.15em 0;
  transform: rotate(45deg);
}

</style>
    